GLite-AMGA
Encyclopedia
The ARDA Metadata Grid Application (AMGA) is a general purpose metadata
catalogue and part of the gLite
middleware
distribution. It was developed by the EGEE project, when it became clear that many Grid
applications needed metadata information on files and to organize a work-flow. AMGA is now developed and supported by a collaboration of CERN
, INFN in Catania and KISTI in Korea.
AMGA as a metadata services allows users to attach metadata information to files stored on the Grid, where metadata can be any relationally organized data typically stored in a relational database system (RDBMS). In addition, the metadata in AMGA can also be stored independently of any associated files, which allows to use AMGA as a general access tool to relational databases on the Grid. AMGA features a simple to learn metadata access language, which has been very useful for the adoption of AMGA in smaller Grid applications, as it lowers the technical hurdle to make use of relational data considerably. Of course also access via SQL92 is supported.
One of the main features of AMGA and unique to it, is the possibility to replicate metadata between different AMGA instances allowing the federation of metadata (e.g. By the Health-e-child project), but also to increase the scalability and improve the access times on a globally deployed Grid (as done by the Wisdom project). Performance and efficiency of the access across WANs has been independently targeted by an access protocol optimsed for the bulk transfer of metadata across WANs using data streaming.
Security on the Grid is a major concern and AMGA features different authentication methods via (Grid-Proxy-) Certificates as well as very flexible accesses control mechanisms for individual data items based on ACLs. In particular these security features have made AMGA the de facto standard for metadata and relational database access on the Grid for biomedical applications. Prominent projects making use of AMGA in this field are Wisdom where AMGA was used in both their campaigns against Avian Flu and malaria, and the Health e-Child project.
Metadata
The term metadata is an ambiguous term which is used for two fundamentally different concepts . Although the expression "data about data" is often used, it does not apply to both in the same way. Structural metadata, the design and specification of data structures, cannot be about data, because at...
catalogue and part of the gLite
GLite
gLite is a middleware computer software project for grid computing used by the CERN LHC experiments and other scientific domains. It was implemented by collaborative efforts of more than 80 people in 12 different academic and industrial research centers in Europe...
middleware
Middleware
Middleware is computer software that connects software components or people and their applications. The software consists of a set of services that allows multiple processes running on one or more machines to interact...
distribution. It was developed by the EGEE project, when it became clear that many Grid
Grid computing
Grid computing is a term referring to the combination of computer resources from multiple administrative domains to reach a common goal. The grid can be thought of as a distributed system with non-interactive workloads that involve a large number of files...
applications needed metadata information on files and to organize a work-flow. AMGA is now developed and supported by a collaboration of CERN
CERN
The European Organization for Nuclear Research , known as CERN , is an international organization whose purpose is to operate the world's largest particle physics laboratory, which is situated in the northwest suburbs of Geneva on the Franco–Swiss border...
, INFN in Catania and KISTI in Korea.
AMGA as a metadata services allows users to attach metadata information to files stored on the Grid, where metadata can be any relationally organized data typically stored in a relational database system (RDBMS). In addition, the metadata in AMGA can also be stored independently of any associated files, which allows to use AMGA as a general access tool to relational databases on the Grid. AMGA features a simple to learn metadata access language, which has been very useful for the adoption of AMGA in smaller Grid applications, as it lowers the technical hurdle to make use of relational data considerably. Of course also access via SQL92 is supported.
One of the main features of AMGA and unique to it, is the possibility to replicate metadata between different AMGA instances allowing the federation of metadata (e.g. By the Health-e-child project), but also to increase the scalability and improve the access times on a globally deployed Grid (as done by the Wisdom project). Performance and efficiency of the access across WANs has been independently targeted by an access protocol optimsed for the bulk transfer of metadata across WANs using data streaming.
Security on the Grid is a major concern and AMGA features different authentication methods via (Grid-Proxy-) Certificates as well as very flexible accesses control mechanisms for individual data items based on ACLs. In particular these security features have made AMGA the de facto standard for metadata and relational database access on the Grid for biomedical applications. Prominent projects making use of AMGA in this field are Wisdom where AMGA was used in both their campaigns against Avian Flu and malaria, and the Health e-Child project.